PSI - Issue 13

Lucie Malíková et al. / Procedia Structural Integrity 13 (2018) 1798–1803 Lucie Malíková & Jan Klusák / Structural Integrity Procedia 00 (2018) 000 – 000

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• the value of the critical load necessary for crack propagation through the MTX/ITZ interface decreases with increasing stiffness of the ITZ layer; • the thicker the ITZ layer, the lower the critical applied load; • the larger the AGG particle, the higher value of the critical force necessary for the unstable crack growth through the MTX/ITZ interface; • neglecting the ITZ (and considering ITZ  MTX) leads to underestimating or overestimating of the critical load.

Fig. 2. Dependence of the critical force values on the elastic mismatch between MTX and ITZ for various combinations of the AGG radius and ITZ thickness calculated by means of the mean tangential stress value fracture criterion.

Fig. 3. Dependence of the critical force values on the elastic mismatch between MTX and ITZ for various combinations of the AGG radius and ITZ thickness calculated by means of the generalized strain energy density factor fracture criterion.

Considering all the dependences mentioned above, following recommendations on the MTX/ITZ/AGG system properties can be stated: in order to obtain as high value of the critical applied load as possible, the ITZ layer should be compliant, thin and the AGG particles should be of larger size. Because the formation of the ITZ and its elastic properties are difficult to affect, at least the size of the aggregates can be controlled. Verification of the results of the numerical study presented in this work is going to be carried out experimentally.